On arrival in a telecommunications station, each optical fiber line cable is directed along cable paths to a rack where it is to be processed. The cable is splayed out at the inlet to a device disposed in the rack and called an optical cable head. In such a cable head, each fiber of the cable is treated individually and is directed via two half-connectors to corresponding opto-electronic equipment. The fibers in the cable are connected to inlets or to outlets of the opto-electronic equipment, as necessary.
The optical cable head device is generally in the form of a simple plate mounted at the top of the rack. The plate carries supports for optical connectors for interconnecting two optical half-connectors, and referred to as centering devices. The centering devices run through the plate transversely and are suitable for receiving the said half-connectors from opposite faces of the plate.
In order to provide a distribution function for the optical fibers of a line cable and for the opto-electronic equipment of a rack using the cable head device, the line cable is splayed out into individual fibers at the cable head device. After ensuring that a spare length of fiber is provided in case subsequent repair is necessary, each individual fiber is terminated with a respective half-connector. Each of these half-connectors is received in one of the centering devices of the plate so that it projects from the rear face of the plate. Optical connection jumpers each provided with a half-connector at each end are used for making connections between the cable optical fibers and the opto-electronic equipment. One of the half-connectors of each jumper is received in one of the centering devices so that it projects from the front face of the plate, and the jumper's other half-connector is received in a connection centering device on the equipment concerned.
This method of providing distribution between the optical fibers of a line cable and opto-electronic equipment suffers from numerous drawbacks. The following drawbacks may be mentioned:
the spare lengths of optical fiber are stored in a disorderly manner in the rack; PA1 the jumpers project forwardly from the front face of the rack, and because of the minimum radius of curvature which must be observed, they tend to get in the way during subsequent operations, in particular when two racks are mounted facing each other; PA1 it is difficult to distribute and repair the fibers behind the plate which is mounted in fixed manner on the rack; PA1 there is the danger of accidents to the eyes of technicians manipulating jumpers by virtue of the light conveyed by the fibers connected to the centering devices on the plate propagating perpendicularly relative to the plate, and in particular from the front face thereof; and PA1 no means are provided for modifying the installation as the capacity of a transmission system grows and with the corresponding growth in the capacity of the line cables it serves; this is because such modifications generally require opto-electronic equipment to be located in several different racks and for the line cable fibers to be distributed in corresponding manner to said different racks, thus requiring splices between fibers having different destination or origin racks.
An aim of the present invention is to provide a cable head device in the form of a cabinet which mitigates the above drawbacks.